The discovery that effective therapeutic agents could be obtained as products resulting from bacterial fermentation has immeasurably increased the armamentarium necessary to maintain the healthy state or to reverse the diseased state. As witness to this is the discovery of penicillin, streptomycin, and also certain anti-tumor agents resulting from microbial fermentation.
Compound 593A is an antibacterial and anti-tumor agent first discovered by Dr. C. O. Gitterman et al. and described in U.S. Pat. No. 3,718,651. The free base of Compound 593A is produced by fermentation of Streptomyces griseoluteus NRRL 3412. Gitterman et al. have described the production, recovery, and characterization of Compound 593A. This patent discloses a procedure which involves extraction of the compound with wet-butanol from concentrated fermentation broth followed by concentration.
The essential features of the present process is the direct absorption of Compound 593A free base on a surface active agent from whole, filtered broth; elution of the compound and further purification by fractional crystallization at controlled pH. The process of this invention affords the isolation of Compound 593A free base in high yield from fermentation broth and permits a facile separation of closely related impurities to give a highly purified product.